checkbox enables/disables submit works only once, jquery

I expect to check/uncheck a checkbox and have it enable/disable a submit button. Javascript fires, doesn't show errors, but the submit input just will not toggle more than once.

JS:

$('#readTerms').change(function() {
    var buttonsChecked = $('#readTerms:开发者_运维知识库checked');
    if (buttonsChecked.length) 
    {
        $('#submitBusiness').removeAttr('disabled');
    } 
    else 
    {
        $('#submitBusiness').attr('disabled', 'disabled');
    }
});

HTML:

<input type="checkbox" id="readTerms" name="agree"> <label for="agree">By checking the box you agree to the <a href="/terms" target="_blank">Terms &amp; Conditions</a>.</label>

<input id="submitBusiness" class="btn positive iconCheck right" type="submit" name="create" value="Submit" disabled="disabled" />

Submit button starts disabled. Click the checkbox and it enables, click the checkbox again and nothing. The if/else statement works fine. The code fires, it trips breakpoints in firebug, etc. etc. etc.

What am I doing wrong?

---

I would try something like this instead:

$('#readTerms').click(function() {
    var buttonsChecked = this.checked;
    if (buttonsChecked == true){
        $('#submitBusiness').removeAttr('disabled');
    }else{
        $('#submitBusiness').attr('disabled', 'disabled');
    }
});

---

Try something like this:

$('#readTerms').change( function() {
  $('#submitBusiness').attr('disabled', !this.checked);
});

Example: http://jsfiddle.net/redler/TETg6/